Ozone Adsorption on Graphene: Ab Initio Study and Experimental Validation

We have investigated ozone adsorption on graphene using the ab initio density functional theory method. Ozone molecules adsorb on the graphene basal plane with a binding energy of 0.25 eV, and the physisorbed molecule can chemically react with graphene to form an epoxide group and an oxygen molecule. The activation energy barrier from physisorption to chemisorption is 0.72 eV, and the chemisorbed state has the binding energy of 0.33 eV. These binding energies and energy barrier indicate that the ozone adsorption on graphene is gentle and reversible. An atomic layer deposition experiment on ozone treated graphite has confirmed the presence of uniform hydrophilic groups on the graphene basal plane. This finding can be applied to diverse chemical functionalization of graphene basal planes.